Magneto-Photonic Sensor Integrated in Hydrogel for Real Time Management of Burn Injuries.

Abstract

In higher degree burns, due to deep dermal damage, the wound healing and re-epithelialization processes are significantly delayed which predisposes open wounds to microbial invasion. Sepsis associated high mortality rate in burn patients implies the lack of effective regi- men for sepsis management. In this study, we propose a theranostic platform comprised of magneto-photonic crytal/MPC hydrogel which allows real-time management of sepsis through integrated biosensing mechanism. Selection of nanocarrier and a rationale to bio- functionlize it was first performed theoretically using Metropolis Monte Carlo method and experimentally by Fourier Transformed Infrared/FTIR spectroscopy to estimate its theranos- tic potential. Simulation & FTIR results suggested successful attachment of dopamine with magnetite and cobalt ferrite nanoparticles in a bidentate bridging configuration. Dopamine was selected as bifunctional linker and its hydroxyl groups bound to the surface of mag- netic nanospheres/MNS of Magnetite and Cobalt ferrite/CoF. Amine groups at the opposite side of dopamine were later utilized for bioconjugation of detecting antibodies. A blend of chitosan and gelatin hydrogel was used to synthesize matrix because of its excellent biocompatibility, wound healing and cell regenerative properties. A nanocomposite of Chitosan-gelatin hydrogel and magnetic nanoparticles was tested for pH responsive drug delivery properties using chlorhexidine gluconate. Electro-analytical methods including Square wave voltammetry, electrochemical impedance spectroscopy & cyclic voltammetry were used to elucidate drug release mechanism. For sepsis detection, we utilized interleukin-6 which is a reported potential biomarker for early detection of sepsis. Through the use of click chemistry, we immobilized antibody against IL-6 on surface of MNS. Colloidal suspension of magneto-photonic crystal was prepared with the application of external magnetic field. Sen- sor response to binding antigen/IL-6 was studied through reflectance spectroscopy & cyclic voltammetry. A quantifiable and well-resolved signal was produced following formation of antigen-antibody complex. Resonant wavelength of CoF and Magnetite underwent blue-shift and reflectance intensity increased up to 50 % and 44 % respectively at a concentration of 50 pg/ml. The dynamic range of sensor is 50-350 pg/ml and it falls within the prognostic values of IL-6 for sepsis detection. The developed integrated sensing mechanism provides an ideal platform for real-time management of sepsis in patients with higher degree burns.